It is possible to change an <element-tag> to an "attribute" with a o.e.p.tools.dbws.NamingConventionTransformer
In the eclipselink-dbwsutils.jar, there are built-in transformers that form a Chain-of-Responsibility

In the org.eclipse.persistence.tools.dbws.NamingConventionTransformer services file, the transformer chain is listed in order: